- Documented pathologic esophageal acid exposure by pH monitoring per institution's standard of care (i.e. total distal ambulatory esophageal pH< 4 for ≥ 5.3% (BRAVO) or ≥4.5% (transnasal) or abnormal DeMeester Score (>14.72) within 12 months of proposed implantation date (After Sleeve Gastrectomy).